Function:
Temporarily disables redraw of the screen after changes to window geometry or window contents.Notes:
It is appropriate to disable updates if you are moving or resizing multiple windows and you want all of the geometry changes to appear onscreen simulataneously. In most other cases, you should strive to avoid disabling screen updates. The window server will automatically re-enable updates (and print a message to the Console log) if you leave updates disabled for a sufficiently long period of time, currently about 1 second.

The window server records the number of calls to DisableScreenUpdates and does not re-enable updates until a matching number of calls to EnableScreenUpdates have been made.

Function:
Re-enables redraw of the screen after changes to window geometry or window contents.Notes:
Screen redraw is not actually enabled until the number of calls to EnableScreenUpdatesMBS matches the number of calls to DisableScreenUpdatesMBS.